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ABSTRACT: Radiofrequency ablation (RFA) is increasingly being used for the treatment of intrathoracic malignancies. Although RFA has been found to be promising in the treatment of lung metastases from some types of neoplasms, little is known concerning its clinical significance in the treatment of pulmonary metastasis from esophageal squamous cell carcinoma (ESCC). This retrospective study evaluated the feasibility, safety, and effectiveness of computed tomography-guided RFA for pulmonary metastasis from ESCC. A series of 10 ESCC patients with 17 pulmonary tumors were included. Correct placement of the ablation device into the target tumor proved to be feasible in all tumors (100%). The mean visual analog scale score, with values that ranged from 0 (no pain) to 10 (worst pain possible), was 1. This suggested that this procedure was well tolerated. No procedure-related deaths occurred. A pneumothorax needing drainage was a major complication in two patients. Local control of ablated tumor lasting for at least 1 year was achieved in 10 (83%) of 12 assessable tumors. Although locoregional recurrences developed in two tumors, these lesions could be recontrolled by repeat treatment with RFA. Three patients died of recurrent disease. The predicted 1- and 2-year overall survival rates after lung RFA were 77.8% and 62.2%, respectively. Percutaneous computed tomography-guided RFA yielded relatively high levels of local control in patients with pulmonary metastases from ESCC and was associated with an acceptable level of complications. It was concluded that a prospective study will be necessary to evaluate the effectiveness of a combination of systemic therapy and RFA for ESCC lung metastases.
Diseases of the Esophagus 02/2013; · 1.81 Impact Factor
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ABSTRACT: We developed a new individually customized contrast-injection protocol for coronary computed tomography (CT) angiography based on the time-attenuation response in a test bolus, and investigated its clinical applicability. We scanned 60 patients with suspected coronary diseases using a 64-detector CT scanner, who were randomly assigned to one of two protocols. In protocol 1 (P1), we estimated the contrast dose to yield a peak aortic attenuation of 400 HU based on the time-attenuation response to a small test-bolus injection (0.3 ml/kg body weight) delivered over 9 s. Then we administered a customized contrast dose over 9 s. In protocol 2 (P2), the dose was tailored to the patient's body weight; this group received 0.7 ml/kg body weight with an injection duration of 9 s. We compared the two protocols for dose of contrast medium, peak attenuation, variations in attenuation values of the ascending aorta, and the success rate of adequate attenuation (250-350 HU) of the coronary arteries. The contrast dose was significantly smaller in P1 than in P2 (36.9 +/- 9.2 vs 43.1 +/- 7.0 ml, P < 0.01). Peak aortic attenuation was significantly less under P1 than under P2 (384.1 +/- 25.0 vs 413.5 +/- 45.7, P < 0.01). The mean variation (standard deviation) of the attenuation values was smaller in P1 than in P2 (25.0 vs 45.7, P < 0.01). The success rate of adequate attenuation of the coronary arteries was significantly higher with P1 than with P2 (85.0 vs 65.8 %, P < 0.01). P1 facilitated a reduction in the contrast dose, reduced the individual variations in peak aortic attenuation, and achieved optimal coronary CT attenuation (250-350 HU) more frequently than P2.
Heart Vessels. 01/2013;
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ABSTRACT: AIM: To optimize low-kilovoltage (kV) computed tomography (CT) protocols using a hybrid iterative reconstruction (HIR) algorithm at 256-detector-row body CT. MATERIALS AND METHODS: Based on preliminary phantom studies, three different tube voltage protocols with an equal contrast-to-noise ratio (CNR) were developed. They were a conventional 120 kV protocol with filtered back-projection (FBP), an 80 kV protocol with HIR (a 160% increase in the tube current-time product and a 40% reduction in the contrast medium dose), and a 100 kV protocol with HIR (a 20% reduction in the tube current-time product and the contrast medium dose). The clinical study included 70 patients (34 women, 36 men; mean age 70.5 ± 9.1 years, range 44-92 years) who had undergone CT at 120 kV a mean of 148 ± 137 days before undergoing low kV contrast-enhanced body CT (80 kV with HIR, n = 35; 100 kV with HIR, n = 35). The estimated effective radiation dose (ED), image noise, and CNR were calculated and the visual image quality was scored on a four-point scale. RESULTS: Mean ED was 12.3, 8.4, and 15.4 mSv for the 80, 100, and 120 kV protocol, respectively, and significantly lower using the low kV protocols. There was no significant difference in the image noise and CNR between the low kV protocols with HIR and the 120 kV protocol with FBP, or in the visual scores among the three protocols. CONCLUSION: Without ensuing image-quality degradation, the radiation and contrast medium dose can be reduced with optimal contrast-enhanced CT protocols using a low kV technique and an HIR algorithm.
Clinical radiology 12/2012; · 1.65 Impact Factor
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H Uetani,
T Hirai,
M Hashimoto,
M Ikeda,
M Kitajima,
F Sakamoto,
D Utsunomiya,
S Oda,
S Sugiyama,
J Matsubara, Y Yamashita
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ABSTRACT: BACKGROUND AND PURPOSE:The prevalence and topography of small hypointense foci suggesting microbleeds on 3T SWI in various types of dementia have not been systematically investigated. The purpose of this study was to determine the prevalence and topography of SHF on 3T SWI in patients with different dementia subtypes.MATERIALS AND METHODS:We included 347 consecutive patients (217 women, 130 men; age range, 42-93 years; mean age, 74 years) who attended our memory clinic and underwent 3T SWI. They were divided into 6 groups: subjective complaints, MCI, AD, DLB, VaD, and FTLD. Two neuroradiologists evaluated the number and location of SHF on SWIs. Statistical analyses were performed to evaluate inter- and intragroup differences.RESULTS:Of the 347 patients, 160 (46.1%) exhibited at least 1 small hypointense focus. This was true in 86% with VaD, 54% with DLB, 48% with AD, 41% with MCI, 27% with FTLD, and 22% with subjective complaints. With the subjective complaints group as a reference, the odds ratio adjusted by age, sex, and arterial hypertension was 9.2 (95% CI, 2.0-43.6) for VaD; 5.4 (95% CI, 1.2-24.3) for AD; 3.1 for DLB (95% CI, 1.1-8.8); 2.0 for MCI (95% CI, 0.5-8.1); and 1.5 for FTLD (95% CI, 0.4-5.4). There was a significant lobar predilection for AD, DLB, and FTLD groups (P < .05).CONCLUSIONS:On 3T SWI, patients with VaD, AD, and DLB manifested a high SHF prevalence. In patients with AD, DLB, and FTLD, the SHF exhibited a lobar predilection.
American Journal of Neuroradiology 11/2012; · 2.93 Impact Factor
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H Uetani,
M Akter,
T Hirai,
Y Shigematsu,
M Kitajima,
Y Kai,
S Yano,
H Nakamura,
K Makino,
M Azuma,
R Murakami, Y Yamashita
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ABSTRACT: BACKGROUND AND PURPOSE:For identifying the arterial feeders of meningiomas, the usefulness of 3D TOF MRA at 3T has not been systematically investigated. This study was intended to assess whether unenhanced 3D TOF MRA at 3T can replace DSA for the identification of arteries feeding intracranial meningiomas and whether it is useful for assessing their dural attachment.MATERIALS AND METHODS:Twenty-one consecutive patients with intracranial meningiomas (18 women, 3 men; aged 42-77 years, mean 57 years) underwent DSA, conventional MR imaging, and 3D TOF MRA. Two neuroradiologists independently evaluated the primary and secondary feeders of each tumor on maximum-intensity-projection and source MRA images. They also identified the location of dural attachments based on information from MR imaging/MRA images. Interobserver and intermodality agreement was determined by calculating the κ coefficient.RESULTS:For the identification of primary and secondary feeders on MRA images, interobserver agreement was very good (κ = 0.83; 95% CI, 0.66-1.00) and moderate (κ = 0.58; 95% CI, 0.34-0.82) and intermodality agreement (consensus reading of MRA versus DSA findings) was excellent (κ = 0.94; 95% CI, 0.84-1.00) and good (κ = 0.72; 95% CI, 0.51-0.93), respectively. With respect to the dural attachment of meningiomas, interobserver agreement was very good (κ = 0.95; 95% CI, 0.84-1.00). The agreement in the diagnosis between MR imaging/MRA and surgery was excellent (κ = 1.00).CONCLUSIONS:Unenhanced 3D TOF MRA at 3T cannot at present supplant DSA for the identification of the feeding arteries of intracranial meningiomas. This information may be useful for evaluating their dural attachment.
American Journal of Neuroradiology 10/2012; · 2.93 Impact Factor
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ABSTRACT: We conducted feeding experiments on threadsail filefish Stephanolepis cirrhifer juveniles for 16days to evaluate the efficacy of moon jellyfish Aurelia aurita as a prey item. Four treatments, each with 40 individuals, were prepared to compare fish growth performance. The treatments
consisted of filefish that were starved (control) (S), fed only jellyfish (J), fed only krill (K), and fed both jellyfish
and krill (JK). Fish in the S treatment exhibited a 50% mortality rate and reduced body weight, whereas the J treatment exhibited
a zero mortality rate and increased body weight. Fish in the JK treatments showed a significantly faster growth than those
in the K treatment. Filefish consumed as much as 24 and 13 times their own body weight in jellyfish per day in the J and JK
treatments, respectively. This is the first report showing that growth can be sustained by feeding a marine fish only jellyfish,
and indicates the potential of jellyfish as a fish prey in both nature and captivity.
Keywords
Aurelia aurita
–Fatty acids–Filefish–Growth–Jellyfish–Monacanthidae–
Stephanolepis cirrhifer
–Survival rate
Fisheries Science 05/2012; 77(1):41-48. · 0.94 Impact Factor
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ABSTRACT: The determination of optical properties of organic matter using spectroscopic techniques is a powerful tool for the characterization
of humic substances (HS) in soils and sediments because of sensitivity, specificity and sample throughput. However, basic
spectroscopic techniques have practical limitations because of the similarity in the optical properties of many HS. To improve
resolution, the combination of excitation-emission matrix (EEM) fluorescence and parallel factor analysis (PARAFAC) was applied
for characterizing fulvic acid (FA) and humic acid (HA) fractions from soils and sediments of two estuarine environments in
Spain. Five fluorescent components were identified by EEM-PARAFAC and were found in both FA and HA fractions, consistent with
the new paradigm of HS as supramolecular associations as well as the ubiquity of the HS components in the environment. Their
contribution was, however, different between the FA and HA fractions. Two different, humic-like, fluorescent components were
representative of FA and HA fractions, respectively. The spectral characteristics of these components were similar to previously
reported PARAFAC components in dissolved organic matter (DOM) in a wide range of environments, suggesting their applicability
in assessing OM quality and environmental dynamics. A microbial humic-like component was much more abundant in FA than in
HA fractions. Furthermore, principal component analysis clarified that the two identified protein-like components, were enriched
in sediment HA compared to soil HA, suggesting a larger contribution of refractory algaenan in sediment HA. The results of
the present study demonstrate that EEM-PARAFAC is a useful technique for the biogeochemical characterization of soil and sedimentary
HS.
Biogeochemistry 04/2012; 96(1):131-147. · 3.07 Impact Factor
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ABSTRACT: Although 3D FLAIR imaging visualizes detailed structures of the brain stem, it has not been used to evaluate its normal anatomy. The purpose of this study was to evaluate whether 3D FLAIR images can provide more detailed anatomic information of the brain stem than 2D FLAIR and 2D T2WI.
We prospectively evaluated MR images in 10 healthy volunteers. 3D and 2D FLAIR images, 2D T2WI, and DTI were obtained on a 3T MR imaging scanner. A VISTA technique was used for 3D FLAIR imaging. White matter tracts and nuclei of the brain stem were determined on 3D and 2D FLAIR images and 2D T2WI by referring to anatomic atlases and DTI color maps. The subjective assessment of the visibility by using a 4-point grading system and the contrast ratio of the structures on 3D and 2D FLAIR images and 2D T2WI were evaluated.
The visibility of the SCP and MCP, DSCP, CST, and CTT was higher on 3D FLAIR images than on 2D T2WI and 2D FLAIR images. The contrast ratio for the CST, SCP, MCP, DSCP, and CTT was significantly different on 3D FLAIR images and 2D T2WI and on 3D FLAIR and 2D FLAIR images; there was no significant difference in contrast ratio for the SCP at the pons on 3D FLAIR and 2D T2WI.
3D FLAIR images provide detailed anatomic information of the brain stem that cannot be obtained on 2D T2WI and 2D FLAIR images.
American Journal of Neuroradiology 01/2012; 33(5):922-7. · 2.93 Impact Factor
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ABSTRACT: Systematic assessment of brain and head and neck tumors with 4D-CE-MRA at 3T has not been investigated. The purpose of this study was to test the hypothesis that 4D-CE-MRA at 3T can replace DSA in the identification of feeding arteries and tumor stain to plan interventional procedures in hypervascular brain and head and neck tumors.
Fifteen consecutive patients with brain and head and neck tumors underwent 4D-CE-MRA at 3T and DSA. 4D-CE-MRA combined randomly segmented central k-space ordering, keyhole imaging, SENSE, and half-Fourier imaging. We obtained 30 dynamic scans every 1.9 seconds at an acquired spatial resolution of 0.9 × 0.9 × 1.5 mm; the matrix was 256 × 256. Two independent observers inspected the 4D-CE-MRA images for the main arterial feeders and tumor stain. Interobserver and intermodality agreement was assessed by κ statistics.
For 4D-CE-MRA, the interobserver agreement was fair with respect to the main arterial feeders and very good for the degree of tumor stain (κ = 0.28 and 0.87, respectively). Intermodality agreement was moderate for the main arterial feeders (κ = 0.45) and good for the tumor stain (κ = 0.74).
Although 4D-CE-MRA may be useful for evaluating tumor stain in hypervascular brain and head and neck tumors, it is not able to replace DSA in planning interventional procedures.
American Journal of Neuroradiology 11/2011; 33(3):445-8. · 2.93 Impact Factor
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T Hirai,
M Kitajima,
H Nakamura,
T Okuda,
A Sasao,
Y Shigematsu,
D Utsunomiya,
S Oda,
H Uetani,
M Morioka, Y Yamashita
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ABSTRACT: QUASAR is a particular application of the ASL method and facilitates the user-independent quantification of brain perfusion. The purpose of this study was to assess the intermodality agreement of TBF measurements obtained with ASL and DSC MR imaging and the inter- and intraobserver reproducibility of glioma TBF measurements acquired by ASL at 3T.
Two observers independently measured TBF in 24 patients with histologically proved glioma. ASL MR imaging with QUASAR and DSC MR imaging were performed on 3T scanners. The observers placed 5 regions of interest in the solid tumor on rCBF maps derived from ASL and DSC MR images and 1 region of interest in the contralateral brain and recorded the measured values. Maximum and average sTBF values were calculated. Intermodality and intra- and interobsever agreement were determined by using 95% Bland-Altman limits of agreement and ICCs.
The intermodality agreement for maximum sTBF was good to excellent on DSC and ASL images; ICCs ranged from 0.718 to 0.884. The 95% limits of agreement ranged from 59.2% to 65.4% of the mean. ICCs for intra- and interobserver agreement for maximum sTBF ranged from 0.843 to 0.850 and from 0.626 to 0.665, respectively. The reproducibility of maximum sTBF measurements obtained by methods was similar.
In the evaluation of sTBF in gliomas, ASL with QUASAR at 3T yielded measurements and reproducibility similar to those of DSC perfusion MR imaging.
American Journal of Neuroradiology 09/2011; 32(11):2073-9. · 2.93 Impact Factor
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S Oda,
K Awai,
Y Funama,
D Utsunomiya,
Y Yanaga,
K Kawanaka,
T Nakaura,
T Hirai,
R Murakami,
H Nomori, Y Yamashita
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ABSTRACT: To investigate the effect of a double-exposure dual-energy subtraction (DES) technique on the diagnostic performance of radiologists detecting small pulmonary nodules on flat-panel detector (FPD) chest radiographs.
Using FPD radiography 41 sets of chest radiographs were obtained from 26 patients with pulmonary nodules measuring <or=20mm and from 15 normal participants. Each dataset included standard and corresponding DES images. There were six non-solid, 10 part-solid, and 10 solid nodules. The mean size of the 26 nodules was 15+/-4.8mm. Receiver operating characteristic (ROC) analysis was performed to compare the performance of the eight board-certified radiologists.
For the eight radiologists, the mean value of the area under the ROC curve (AUC) without and with DES images was 0.62+/-0.05 and 0.68+/-0.05, respectively; the difference was statistically significant (p=0.02). For part-solid nodules, the difference of the mean AUC value was statistically significant (AUC=0.61+/-0.07 versus 0.69+/-0.05; p<0.01); for non-solid nodules it was not (AUC=0.62+/-0.1 versus 0.61+/-0.09; p=0.73), and for solid nodules it was not (AUC=0.75+/-0.1 versus 0.78+/-0.08; p=0.23). For nodules with overlapping bone shadows, the difference of the mean AUC value was statistically significant (p=0.03), for nodules without overlapping, it was not (p=0.26).
Use of a double-exposure DES technique at FPD chest radiography significantly improved the diagnostic performance of radiologists to detect small pulmonary nodules.
Clinical radiology 08/2010; 65(8):609-15. · 1.65 Impact Factor
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ABSTRACT: The usefulness of contrast-enhanced 3D T2-FLAIR MR imaging for the evaluation of leptomeningeal diseases has not been systematically investigated. The purpose of this study was to assess the value added by contrast-enhanced 3D T2-FLAIR and MPRAGE sequences to conventional postcontrast T1-weighted images in the evaluation of leptomeningeal diseases. We also undertook in vitro studies in attempts to understand the consequences of our patient study.
Twelve patients with confirmed leptomeningeal diseases underwent postcontrast T1-weighted, MPRAGE, and 3D T2-FLAIR imaging at 3T. Two radiologists independently assessed the presence of additional information on postcontrast 3D MR images compared with postcontrast T1-weighted images. The effect of different Gd concentrations and flow velocities on the signal intensity on 3D T2-FLAIR images was investigated in vitro.
According to both reviewers, 3D T2-FLAIR images yielded significantly more information than did MPRAGE images (P < .05 and P < .01, respectively). In the in vitro study, 3D T2-FLAIR was more highly sensitive to low Gd concentrations and less sensitive to high Gd concentrations than were T1-weighted or MPRAGE sequences. On 3D T2-FLAIR sequences, at a flow velocity exceeding 1.0 cm/s, the signal intensity of blood-mimicking fluids at concentrations of 0 and 0.1 mmol/L was as low as at 1.3 mmol/L.
For the depiction of leptomeningeal diseases, postcontrast 3D T2-FLAIR provides more additional information than postcontrast MPRAGE imaging. The superiority of the 3D T2-FLAIR sequence is associated with its high sensitivity to flow.
American Journal of Neuroradiology 05/2010; 31(5):868-73. · 2.93 Impact Factor
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ABSTRACT: Purpose: to evaluate histological changes and duration of enhancement after the intra-arterial injection of helium gas microbubbles in comparison with conventionally used carbon dioxide (CO2) microbubbles at US Material and Methods: Four different doses of helium gas microbubbles (0, 0.1, 0.2 and 0.5 ml/kg) mixed with normal saline and own blood were injected into the celiac artery of 8 rabbits. After one week, autopsies were performed on all animals and histological changes in the liver, stomach and spleen were studied on hematoxylin-eosin stains. in addition, VX-2 tumor strains were transplanted into the femoral muscle in 5 other rabbits. Four weeks after transplantation, we catheterized the femoral artery and either CO2 or helium gas microbubbles were injected under US observation. We evaluated the duration of enhancement in the tumors with the two types of microbubbles Results: on histological evaluation, damage in hepatic cells as well as multiple areas of gastritis in the stomach were seen when a dose of 0.5 ml/kg of helium gas was used. Damage in the liver and stomach was slight at a dose of 0.2 ml/kg. the spleen was not damaged at doses of under 0.5 ml/kg. in the evaluation of tumor enhancement, the duration of enhancement with helium gas microbubbles ranged from 28 to 45 min (average 36 min) while that with CO2 ranged from 4 to 12 min (average 9 min) (p>0.001 at paired t-test) Conclusion: Intra-arterial injection of helium gas should not exceed 0.2 ml/kg: a dose of 0.5 ml/kg may cause damage to the liver and stomach. the duration of enhancement with helium gas microbubbles is significantly longer than that with CO2 microbubbles
01/2010; 39(1):96-99.
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S Nishimura,
T Hirai,
A Sasao,
M Kitajima,
M Morioka,
Y Kai,
Y Omori,
T Okuda,
R Murakami,
H Fukuoka,
K Awai,
J-I Kuratsu, Y Yamashita
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ABSTRACT: Four-dimensional contrast-enhanced MR angiography (4D-CE-MRA) at 3T may replace digital subtraction angiography (DSA) for certain diagnostic purposes in patients with intracranial dural arteriovenous fistula (DAVF). The aim of this study was to test the hypothesis that 4D-CE-MRA at 3T enables the same characterization of intracranial DAVFs as DSA.
The study population consisted of 18 consecutive patients with intracranial DAVFs (11 women, 7 men; age range, 35-82 years; mean age, 64.8 years). They underwent 4D-CE-MRA at 3T and DSA. The 4D-CE-MRA series combined randomly segmented central k-space ordering, keyhole imaging, sensitivity encoding, and half-Fourier imaging. We obtained 30 dynamic scans every 1.9 seconds with a spatial resolution of 1 x 1 x 1.5 mm. Two independent readers reviewed the 4D-CE-MRA images for main arterial feeders, fistula site, and venous drainage. Interobserver and intermodality agreement was assessed by kappa statistics.
At DSA, 8 fistulas were located at the transverse sigmoid sinus; 8, at the cavernous sinus; and 2, at the sinus adjacent to the foramen magnum. Interobserver agreement was fair for the main arterial feeders (kappa = 0.59), excellent for the fistula site (kappa = 0.91), and good for venous drainage (kappa = 0.86). Intermodality agreement was moderate for the main arterial feeders (kappa = 0.68) and excellent for the fistula site (kappa = 1.0) and venous drainage (kappa = 1.0).
The agreement between 4D-CE-MRA and DSA findings was good to excellent with respect to the fistula site and venous drainage.
American Journal of Neuroradiology 10/2009; 31(1):80-5. · 2.93 Impact Factor
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A Sasao,
T Hirai,
S Nishimura,
H Fukuoka,
R Murakami,
M Kitajima,
T Okuda,
M Akter,
M Morioka,
S Yano,
H Nakamura,
K Makino,
J-i Kuratsu,
K Awai, Y Yamashita
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ABSTRACT: The vascular supply of extra-axial brain tumors provided by the external carotid artery has not been studied with RPI. The purpose of this work was to determine whether RPI assessment is feasible and provides information on the vascular supply of hypervascular extra-axial brain tumors.
Conventional ASL and RPI studies were performed at 3T in 8 consecutive patients with meningioma. On the basis of MRA results, we performed RPI by placing a selective labeling slab over the external carotid artery. Five patients underwent DSA before surgery. Two neuroradiologists independently evaluated the overall image quality, the degree of tumor perfusion, and the extent of the tumor vascular territory on conventional ASL and RPI.
In overall quality of conventional ASL and RPI, no images interfered with interpretation. In comparisons of the vascular tumor territory identified by the conventional ASL and RPI techniques, the territories coincided in 3 cases, were partially different in 4, and completely different in 1. The interobserver agreement was very good (kappa = 0.82). In 5 patients who underwent DSA, the 4 patients in whom the dominant supply was the external carotid artery were scored as coincided or partially different. The 1 patient in whom the vascular supply was from the internal carotid artery was scored as completely different.
RPI with selective labeling of the external carotid artery is feasible and may provide information about the vascular supply of hypervascular extra-axial brain tumors.
American Journal of Neuroradiology 10/2009; 31(3):554-8. · 2.93 Impact Factor
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ABSTRACT: Summary Percutaneous microwave coagulation therapy (PMCT) is a new therapeutic technique for the treatment of solid neoplasms. In this report, we present our 5 years' experience with PMCT for the treatment of 69 hepatocellular carcinomas (HCCs) in 60 patients. Under ultrasonic guidance, we inserted a 2.1 mm guiding needle percutaneously toward the lesion and a needle electrode was precisely positioned within the lesion. Microwaves, with a frequency of 2450 MHz, were produced for 60 s, with 60 W emission. The overall success rate was 72%, the mean disease-free period was 24.2 months. The procedures were safe and tolerable for all patients. Slight pain and heat sensation were encountered in most patients. We consider PMCT an effective and safe treatment for HCCs.
07/2009; 7(6):541-546.
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ABSTRACT: To determine the optimal contrast medium injection protocol for demonstrating the Adamkiewicz artery (AKA) using 64-detector CT angiography (CTA).
CTA was performed using 64-detector CT. The study population consisted of 80 patients (mean age 67.2 years) with aortoiliac diseases. In the first 60 patients 540 mg I/kg body weight was administered over 25s. The patients were randomly assigned to three protocols with imaging started at 15 (protocol A-1), 18 (A-2), or 21s (A-3) after triggering (threshold 150 HU). The other 20 received 720 mg I/kg body weight with an imaging delay of 18s (protocol B). Two radiologists evaluated the presence of the AKA and measured the attenuation of the aorta and AKA.
Aortic enhancement was 360.4, 348, 279.3, and 372 HU for protocols A-1, A-2, A-3, and B, respectively. There was no significant difference between the A-1 and A-2 protocols (Tukey-Kramer test, p=0.73); however, aortic enhancement was significantly lower in A-3 than A-1 and A-2 (p<0.01). There was no significant difference between A-2 and B (p=0.40). AKA attenuation was 69.3, 91.9, 94.6, and 105.4 HU for protocols A-1, A-2, A-3, and B, respectively. There was no significant difference between the A-2 and A-3 protocols (p=0.91); however, AKA attenuation was significantly lower with A-1 than A-2 or A-3 (p=0.01). AKA attenuation was significantly lower with A-2 than B (p=0.03) and there was a significant difference between A-2 (50%) and B (95%) in the depiction of the hairpin configuration of the AKA (p=0.02).
For the demonstration of the AKA at CTA, the optimal protocol used an imaging delay of 18s after triggering and an iodine dose of 720 mg I/kg body weight.
Clinical radiology 08/2008; 63(8):880-7. · 1.65 Impact Factor
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R Murakami,
H Uozumi,
T Hirai,
R Nishimura,
S Katsuragawa,
S Shiraishi,
R Toya,
K Tashiro,
K Kawanaka,
N Oya,
S Tomiguchi, Y Yamashita
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ABSTRACT: Although gross tumor volume (GTV) at the primary site can predict local control of head-and-neck squamous cell carcinoma (SCC) in patients who are treated with organ-preservation therapy, GTV assessment does not eliminate substantial interobserver variation.
To evaluate whether F-18-fluorodeoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT) fused imaging provides additional information for GTV assessment.
We obtained FDG-PET/CT fused images on 20 patients with head-and-neck SCC. All had undergone preoperative conventional workup, including contrast-enhanced CT and magnetic resonance imaging (MRI). The GTV of the primary tumors was designed by two independent observers who used routine clinical data. Observer A was a radiologist and observer B a radiation oncologist. GTV1 and GTV2 were designed without and with FDG-PET/CT, respectively. For geometric interobserver comparison, we calculated the concordance rate as the ratio of the intersection (AxB) of the GTVs to their union (AxB). Intermethod (GTV1 vs. GTV2) and interobserver (A vs. B) differences in the GTVs were assessed by Bland-Altman analysis and the Spearman rank-correlation test. The interobserver concordance rates for GTV1 and GTV2 were compared using a two-tailed paired-samples t test.
On FDG-PET/CT, all primary tumors were visualized. There was no systemic trend for a volume difference between GTV1 and GTV2. Although the 95% limits of agreement were wider for interobserver than intermethod differences, the 95% limits of interobserver agreement were narrower for GTV2 than GTV1. The mean interobserver concordance rate for GTV2 was higher than for GTV1 (54.5% vs. 39.1%, P=0.0002).
FDG-PET/CT is a useful modality for consistent GTV assessment, which should not be used as a single modality but rather to obtain supplemental information in patients with head-and-neck SCC.
Acta Radiologica 08/2008; 49(6):693-9. · 1.37 Impact Factor
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T Hirai,
R Murakami,
H Nakamura,
M Kitajima,
H Fukuoka,
A Sasao,
M Akter,
Y Hayashida,
R Toya,
N Oya,
K Awai,
K Iyama,
J-i Kuratsu, Y Yamashita
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ABSTRACT: Although the prognostic value of perfusion MR imaging in various gliomas has been investigated, that in high-grade astrocytomas alone has not been fully evaluated. The purpose of this study was to evaluate retrospectively whether the tumor maximum relative cerebral blood volume (rCBV) on pretreatment perfusion MR imaging is of prognostic value in patients with high-grade astrocytoma.
Between January 1999 and December 2002, 49 patients (30 men, 19 women; age range, 23-76 years) with supratentorial high-grade astrocytoma underwent MR imaging before the inception of treatment. The patient age, sex, symptom duration, neurologic function, mental status, Karnofsky Performance Scale, extent of surgery, histopathologic diagnosis, tumor component enhancement, and maximum rCBV were assessed to identify factors affecting survival. Kaplan-Meier survival curves, the logrank test, and the multivariate Cox proportional hazards model were used to evaluate prognostic factors.
The maximum rCBV was significantly higher in the 31 patients with glioblastoma multiforme than in the 18 with anaplastic astrocytoma (P < .03). The 2-year overall survival rate was 67% for 27 patients with a low (< or =2.3) and 9% for 22 patients with a high (>2.3) maximum rCBV value (P < .001). Independent important prognostic factors were the histologic diagnosis (hazard ratio = 9.707; 95% confidence interval (CI), 3.163-29.788), maximum rCBV (4.739; 95% CI, 1.950-11.518), extent of surgery (2.692; 95% CI, 1.196-6.061), and sex (2.632; 95% CI, 1.153-6.010).
The maximum rCBV at pretreatment perfusion MR imaging is a useful clinical prognostic biomarker for survival in patients with high-grade astrocytoma.
American Journal of Neuroradiology 06/2008; 29(8):1505-10. · 2.93 Impact Factor
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ABSTRACT: We performed superselective intra-arterial infusion chemotherapy (SIC) according to a protocol in which drug distribution is evaluated by the use of interventional radiology (IVR)-computed tomography (CT) system, and the chemotherapy is combined with medium-dose conformal radiation therapy (CRT). We analyzed retrospectively the factors that affect the midterm survival ratio, including local response, for stage III and IV squamous cell carcinomas of the oral cavity.
Forty consecutive patients with stage III and IV squamous cell carcinomas of the oral cavity and who had undergone both SIC and CRT were enrolled. A microcatheter was placed in the appropriate feeding artery of the tumor and cisplatin (50mg/body) was infused twice. CRT was administered with a dual-energy (4 and 10 MV) linear accelerator. The total and daily doses delivered were 30 and 2.0 Gy, respectively. Histopathologic effects were classified into five grades: grade 0 or 1 was defined as a poor response, and grade II or higher as a good response. Age, sex, stage, local response to treatment, mode of invasion and lymph node metastasis were analyzed, and differences in the midterm survival ratio were assessed.
The 3-year survival ratio of the 40 cases was 67%. A good local response (III or IV) was achieved in 75% of the cases. The survival ratio of the good local response group was significantly better than that of the poor response group (p=0.04). Mode of invasion (p=0.03) and lymph node metastasis (p=0.01) were also predictive of survival. In the multivariable analysis of survival, however, no variables including good local response (p=0.12), were predictive.
Our new protocol improved local response, but it did not contribute to the survival ratio.
European Journal of Radiology 05/2008; 66(1):7-12. · 2.61 Impact Factor
